Desktop computing devices, laptop and other portable computers, smartphones and other hand-held devices, and other electronic devices are typically equipped to receive electronic communications, such as electronic mail (e.g. “email”), text messages, or the like. With the advent of large scale wireless and wireline networks, and a cornucopia of such electronic communication devices in use over the globe, reaching other people has never been easier. Email has become one of the best mediums for individuals, companies, advertisers or other entities to locate a desired audience for advertisement and solicitations. However, it is often the case that the targeted recipients of such communications did not solicit, nor do they want to receive, communications from such entities. The indiscriminate distribution of such electronic communications is colloquially referred to as junk email, “spam,” unsolicited bulk email, etc.
Email providers, such as web-based email providers, attempt to manage such unsolicited email on behalf of their registered users. Local email clients may also include software to attempt to identify and filter unwanted email messages. Identifying and properly filtering unsolicited email and other electronic messages has proven to be a substantial task, as the sources of unsolicited email continue to seek ways to make their communications look legitimate, or at least to make them difficult to identify as illegitimate.